Because it's a writing challenge.
Are you able to write content that is relatable, contrarian/unique, and timely?
If you can write in a manner that appeals to a large audience, you can certainly narrow down and write for your target audience.
Understanding the effect of your writing is important for delivering value. What response do you want from your reader?
Often I see that posts that perform very well offer a unique insight that goes against the majority's thought. This is a fantastic skill to master.
Your writing should never appease everyone, if it does, it's not really an "original" thought and won't have a significant impact on the reader.
Viral posts depend on being relevant and timely. For example, there's been a lot of media attention about Twitter and Elon Musk, this past week would have been perfect to say something relatable and unique about it. But in 3 weeks from now? Probably won't work (unless Elon rocks the boat more).
It's still a bit like the Wild West, the quickest shooter wins.